Question

marta must memorize 30 measures of music for her cello solo at a concert. she plans on memorizing 13 new measures for every 3 days of practice. which equation can be used to determine m, the number of measures she will need to memorize, as a function of d, the number of days of practice since she began learning the piece?
a) m = 30 - 13d
b) m = 30 - 5d
c) m = 30 - 2d
d) m = 30 - 3d

Explanation:

Step1: Find the number of measures memorized per day

She memorizes 15 new measures every 3 days. So the number of measures memorized per day is $\frac{15}{3}=5$.

Step2: Set up the linear - equation

She starts with 30 measures to memorize. The number of measures $m$ she still needs to memorize is the initial number of measures minus the number of measures she has memorized. The number of measures she has memorized after $d$ days is $5d$. So the equation is $m = 30-5d$.

Answer:

$m = 30 - 5d$